Sunday, September 20, 2015

Recently, a series of advertisements came into the public
consequence. These images depict women breastfeeding, with one breast painted
to look like a hamburger, doughnut, or can of soda. The message is “Your child is
what you eat”, suggesting that the mother’s diet is directly related to the
construction of the baby – that is, eat a burger, build a baby from burgers.

Before we get into a discussion of the factual accuracy of
the statement, it is worth taking a moment to think about the ads themselves.
The ads were most likely produced by the advertising company PAIM, and the logo
depicted is that of the SPRS – the Pediatric Society of Rio Grande (Brazil).
SPRS is sponsored by Nestle, and there is some evidence that PAIM also holds
the Nestle ad campaign for Brazil. But here’s my big question: why are the ads
in English? The national language of Brazil is Portuguese, and as of 2011, the
best guess for English fluency among educated Brazilians was 8-11% (Glickhouse,
2012). Your milk what you eat should be “Seuleiteéo que você come” (if Google
translate is accurate).

Although the images contain the logo for SPRS and a link to
the website, the ads are not on the SPRS website. The SPRS website is also in Portuguese.
Moreover, the food images just don’t quite match up to typical Brazilian
cuisine – burgers commonly have eggs or corn for example, and doughnuts with holes
in the middle are not that common in Brazil. So – just who were those ads
designed for?

Leaving aside this very big question, the ads have generated
considerable international attention and debate. Many mothers have expressed
concern about the message: your baby is what you eat. But is it true? Well, the
best answer is “somewhat – but not really”, at least as a far as breast milk is
concerned.

Breast milk is produced by the mothers’ body (for review,
see my prior post here). Generally, the proteins and sugars in the milk are
largely independent of what the mother eats. This reflects the synthesis of
protein and sugar by specialized cells, called lactocytes, in the breast.
Synthesis occurs from glucose, amino acids, and similar. Very few dietary or lifestyle
factors appears to influence milk protein, especially milk proteins that are
not immunoproteins.

Total milk fat, at least for humans, is largely independent
of the mother’s diet (Villalpando and Del Prado, 1999). However, the fatty acid
composition of the milk fat is strongly correlated with the maternal diet.

Probably the best known example is that of DHA. Most pre-
and post-natal vitamins contain fish oils or DHA. DHA is a long chain,
polyunsaturated fatty acid that cannot be produced by the mother’s body and
must be derived from her diet. Ergo, milk DHA is very sensitive to the mother’s
diet – more dietary DHA, more DHA in milk. Figure 1 shows an example from our
work in the Philippines (Quinn et al., 2012), where we found a dose association
between meals of a local fish (bodboron) and milk DHA. If you haven’t heard of bodboron,
don’t be surprised – in the US, it is commonly fed to salmon rather than consumed.
Working with mothers in Denmark, Lauritzen et al., (2002) also showed a
positive association between fish consumption (in this case salmon) and milk
DHA. Fish oil consumption has long been recognized as a source of milk DHA
(Harris et al., 1984). It is also understood that fatty acids – especially long
chain fatty acids like DHA – accumulate in body fat where they can be utilized
later.

What if a mother is consuming a diet that is very low in
fat? There is no substantial evidence that her total milk fat will be lower
(Villalpando and Del Prado 1999). This is another one of those instances where
mothers’ bodies are amazing – her body will produce certain fatty acids from
glucose derived from the carbohydrates in her diet. Humans cannot produce long
chain fatty acids like DHA – but the breast and liver can produce medium chain
fatty acids – fatty acids with less than 14-16 carbons (Figure 2). These medium chain fatty acids are routinely
incorporated into milk fat, and, when dietary and existing fat stores are
insufficient to meet demand, the mother’s body will produce more medium chain
fatty acids to maintain milk fat (Rudolph et al., 2007). Thus, total fat is
maintained, even if fatty acid composition is altered.

Figure 2: Comparison of two fatty acids - TOP: lauric acid, which has a carbon chain length of 12 and can be produced by the mammary gland and liver, and BOTTOM: DHA, which cannot be produced by the body.

Another concern would be man-made food products, like
trans-fatty acids or artificial sweetners (up next!). These have been found in
human milk; and there is general concern about the levels of trans-fatty acids
in human milk. Product labeling has resulted in lower dietary intakes and a
reduction in milk trans-fatty acids in Canadian mothers (Ratnayake et al.,
2014); a recent analysis of some 2327 food products in Brazil found that more
than half contained trans-fatty acids. The worst offenders were cookies, so if
this was really an ad about trans-fatty acids, a cookie would be the
appropriate image.

What does it come back to? These advertisements are making
the same fictional point we have discussed here before with medical devices. You
are a threat to your baby. Your body can’t be trusted. You can’t be trusted to
eat right for your baby and thank heavens there is formula so you can’t harm
your baby with your hamburgers. These
ads are deliberate, and the target audience is very much open for debate.